The present invention relates generally to methods and apparatus for maintaining a sanitary condition in an ice maker and beverage dispenser, and in particular to such methods and apparatus using ozone as a sanitizing agent.
The need to keep ice making and dispensing and beverage dispensing equipment clean over time is well known in the art. It is understood that such equipment can become contaminated with microorganisms, such as, bacteria, yeast, fungi, and mold. Thus, for example, the ice forming evaporator, fluid lines and ice storage area found in such equipment must be periodically cleaned. In the case of beverage dispensers, overflow beverage can promote the growth of microorganisms resulting in the clogging of the drains thereof.
Manual cleaning with detergents and sterilizing chemicals can be effective, however, cleaning schedules are not, as a practical matter, always adhered to. In addition, the job may not be done satisfactorily in terms of a thorough cleaning and rinsing of the food contact and drain elements or tubes. Thus, systems have been developed including electronic controls that, in the case of an ice maker, automatically enter the machine into a sanitizing cycle wherein cleaning agents are pumped there through and subsequently rinsed off. Of course, the automatic systems can fail as well, where, for example, the cleaning agent reservoir runs out of cleaner, or the apparatus simply breaks down or fails to operate properly. Moreover, cleaning of the drains thereof is not specifically addressed or provided for in the prior art.
The use of ozone (O3) as a sanitizing/oxidizing agent is well known, and especially its use to kill microorganisms in water. In ice machines, ozone has been used wherein a venturi is placed in the water line that runs from the water pump to the water distribution manifold. An ozone generator is connected to the venturi injector so that O3 can be entrained into the water as it flows there through. Thus, O3 is carried by the water over the ice making evaporator for providing some bactericidal or bacteriostatic effect. However, there is a need to provide for an ice maker and/or beverage dispenser wherein the ozone generator is an integral part thereof and where the produced ozone can be utilized more effectively so as to maintain a sufficient bacteriostatic condition. Furthermore, the is a need in the prior art to provide for such equipment having an extended life with respect to the ozone generator and to be resistant to any oxidation resulting from the presence of ozone in and around such equipment.
The present invention is an apparatus and method for providing effective ozonation of water used in ice making equipment for the production of ice cubes and for the ozonation of ice retaining bins for sanitizing and retarding the growth of micro-organisms therein and in the drains of beverage dispensing equipment.
In one embodiment of the present invention, a combination ice/beverage dispensing machine has an ice maker secured to a top end of a beverage dispenser. The ice maker produces ice that is dropped into and fills an ice retaining bin within the beverage machine. This type of combination is well known in the art and eliminates the need for manual loading of ice into the beverage dispensing machine.
As is also known, an ice maker typically includes a refrigeration component section and an ice making section separated by a dividing panel. The refrigeration component section includes a compressor, a condenser and fan and the associated electronics used for the operation thereof. An ice cube forming evaporator is located in the ice making section and includes a water distribution tube and a water receiving tank. As is known in the art, the ice maker as above described, includes a water pump that operates to pump water from a source thereof to the water distribution tube. The water then cascades over the surface of the evaporator. As the evaporator is cooled by operation of the refrigeration components, some of the water flowing there over will freeze thereon. The remainder of the water will flow into the receiving tank to be recycled by the pump to flow repeatedly over the evaporator until ice of a sufficient thickness is formed thereon. The ice is then harvested, typically by hot gas defrosting of the evaporator, causing the ice to melt slightly and slip off the evaporator and drop into the ice retaining bin of the beverage dispenser.
As is further understood, the beverage machine includes a plurality of beverage dispensing valves secured along a front surface thereof and includes a drip tray there below. An ice-dispensing chute typically extends from the same front surface and located centrally of the beverage valves. An ice delivering mechanism provides for transfer of ice from the ice retaining bin into the chute, which mechanism is activated when a cup, to be filled with ice, is placed below an open end of the ice chute. Any spillage of ice or beverage is caught by the drip tray and directed down a drain tube connected thereto. The ice bin includes a cold plate for receiving ice from the ice retaining bin for providing heat exchange cooling of the fluid beverage components flowing through individual tubes retained within the cold plate.
A merchandising structure is also secured to the front surface of the ice/beverage dispenser at a level thereon above that of the beverage valves. The merchandising structure includes a frame having a merchandising window to which various advertising transparencies can be secured. The transparencies are generally illuminated by means of back lighting thereof wherein a fluorescent bulb is secured to the ice/beverage dispenser front surface behind the transparency. The merchandising structure can be removed to reveal an interior panel. The panel is secured by means of a pivot hinge to the dispenser front surface and includes thereon-electrical sockets for engaging and retaining the fluorescent bulb. The panel can be swung down and open to reveal a component retaining area. An ozone generating device is secured within this component area. An appropriate electrical power supply circuit is retained in the component area and provides the correct power level necessary to operate the ozone generator. The ozone generator includes an air inlet and an air outlet. As is well understood regarding ozone generation in general, oxygen (O2.) travels into the inlet so that the high electrical potential of the interior of the generator can result in the production of ozone (O3) from the ambient air. The O3 then travels out of the generator outlet. In the present invention, an air pump is secured to the inlet of the ozone generator. The outlet is secured to a tube running to the air inlet of a venturi. The venturi is located in the ice making machine in the refrigeration component section, and includes a water inlet and a water outlet. The venturi is fluidly connected in the stream of water running from the pump to the ice maker distribution tube. Thus, the water line running from the outlet of the pump is secured to the inlet of the venturi and the outlet of the venturi is secured to a tube extending to the water distribution tube.
In operation, the air pump provides a driving force for the O3 produced by the ozone generator to flow into the air inlet of the venturi. During the time that ice is being produced, the water pump causes a flow of water through the venturi. Thus, the suction force produced by the venturi effect coupled with the driving force provided by the air pump was found to finely entrain very minute bubbles of the now O3 rich air into the water. This O3 rich water then flows into the water distribution tube over the evaporator. It was found that by enriching the O3 content of the water in this manner using an air pump to provide for such improved mixing thereof, rather than rely on the inherent suction effect of the venturi alone, that sufficient quantities of O3 would reach the water distribution tube, the evaporator and the receiving tank such that growth of microorganisms thereon was greatly reduced or eliminated.
In the above described embodiment a T-fitting can be used wherein a portion of the ozone produced by the generator is directed to a tube that ends at a fitting secured to a top edge of the ice retaining bin of the beverage dispenser. Thus, O3 laden air is moved by the air pump up to and out of the ice bin fitting. As O3 molecules are heavier than air, they fall under the force of gravity into the bin. It was found that the microorganism content of the bin and the water drain tube and growth thereon or therein was greatly reduced or eliminated. It was also discovered that such content and growth in the drip tray and associated drain tube was reduced or eliminated. In particular, the clogging type of growth in the drain tubes was not found to re-occur.
In the above described embodiment it was found that the bacteriostatic or bactericidal effects of the ozone were maximized in a method of operation wherein the ozone generator and the air pump ran continuously regardless if the ice maker was in an ice making mode or not. When not in the ice making state, i.e. when the water pump was not operating, the O3 laden air did not mix with the water as well, however it would flow from the venturi in a reverse direction through the water pump into the receiving tank. At the same time it would flow in the xe2x80x9cnormalxe2x80x9d direction from the venturi and up to the water distribution tube. Of course, a larger amount of O3 would, during non ice making times, also flow into the ice retaining bin, as less would be demanded due to the absence of the suction effect of the venturi. When long ice maker off periods are encountered, a modification can be made to allow the water pump and venturi (along with the generator and air pump that are already energized) to operate when the unit is not making ice. This will permit continued circulation of O3 containing water over the evaporator as if the ice maker were in an ice making mode.
In a second embodiment of the present invention, an ice maker and ice/beverage combination as above described is used, except no venturi is utilized and ozone is moved by the air pump only. In this further embodiment a tube runs directly from the outlet of the ozone generator to a fitting which enters into the water distribution tube that is located at the top perimeter edge of the ice making compartment. In this embodiment the O3 laden air is more xe2x80x9cpassivelyxe2x80x9d mixed with the ice making water, than in the first embodiment where a venturi is utilized. However, by using the strategy of also running the ozone generator continuously, it was found that a direct connection to the distribution tube also served to provide for a substantial reduction in microorganisms present or growing on or in the water distribution tube, the evaporator, the receiving tank and the pump and associated tubing. This embodiment was also found to reduce or eliminate the presence of microorganisms in the ice retaining bin and associated drain tubing, as well as in the ice dispensing chute, cold plate drains, drip tray and drain tube thereof.
In a third embodiment of the present invention, a beverage machine as above described is used, except no ice machine is secured to the top thereof. In this embodiment an ozone generator and air pump are used to feed a line running to a fitting secured to the top perimeter edge of the ice dispensing hopper. This embodiment was also found to reduce or eliminate the presence of microorganisms in the ice retaining bin and associated drain tube as well as in the ice dispensing chute, drip tray and drain tube thereof.
In a fourth embodiment, a drop in type beverage dispenser has an integral ozone generating system located in the tower portion thereof. The ozone is distributed to the ice bin and drip tray portions thereof for providing a germicidal effect therein.